1028
B . R . HONOVSKI.
For the purpose of detecting minute traces of benzoic acid, an aqueous solution of copper propionate was employed. Preliminary tests had shown that this reagent was capable of giving a distinct precipitate in a neutral solution of benzoic acid a t a dilution of I : 10,000. Since no precipitate was formed in the 30 cc. portion of neutral solution, benzoic acid, if produced a t all in the reaction, must have been present in an amount less than 0.006 g.
Conclusions. The action of an alkyl (or aryl) halide upon magnesium in the presence of an ether results in the formation of certain addition products which may be represented by the general formula n R )OM
